.\" Copyright (C) Nominum, Inc.
.\"
.\" All rights reserved.
.TH DNSPERF 1 "Dec 9, 2015" Nominum Nominum
.SH NAME
\%dnsperf - test the performance of a DNS server
.SH SYNOPSIS
.hy 0
.ad l
\fBdnsperf\fR\ [\fB\-a\ \fIlocal_addr\fB\fR]
[\fB\-b\ \fIbufsize\fB\fR]
[\fB\-c\ \fIclients\fB\fR]
[\fB\-d\ \fIdatafile\fB\fR]
[\fB\-D\fR]
[\fB\-e\fR]
[\fB\-f\ \fIfamily\fB\fR]
[\fB\-h\fR]
[\fB\-l\ \fIlimit\fB\fR]
[\fB\-n\ \fIruns_through_file\fB\fR]
[\fB\-p\ \fIport\fB\fR]
[\fB\-q\ \fInum_queries\fB\fR]
[\fB\-Q\ \fImax_qps\fB\fR]
[\fB\-s\ \fIserver_addr\fB\fR]
[\fB\-S\ \fIstats_interval\fB\fR]
[\fB\-t\ \fItimeout\fB\fR]
[\fB\-T\ \fIthreads\fB\fR]
[\fB\-u\fR]
[\fB\-v\fR]
[\fB\-x\ \fIlocal_port\fB\fR]
[\fB\-y\ \fI[alg:]name:secret\fB\fR]
.ad
.hy
.SH DESCRIPTION
\fBdnsperf\fR is a DNS server performance testing tool. It is primarily
intended for measuring the performance of authoritative DNS servers, but it
can also be used for measuring caching server performance in a closed
laboratory environment. For testing caching servers resolving against the
live Internet, the \fBresperf\fR program is preferred.

It is recommended that \fBdnsperf\fR and the name server under test be run
on separate machines, so that the CPU usage of \fBdnsperf\fR itself does not
slow down the name server. The two machines should be connected with a fast
network, preferably a dedicated Gigabit Ethernet segment. Testing through a
router or firewall is not advisable.
.SS "Configuring the name server"
If using \fBdnsperf\fR to test an authoritative server, the name server
under test should be set up to serve one or more zones similar in size and
number to what the server is expected to serve in production.

Also, be sure to turn off recursion in the server's configuration (in BIND
8/9, specify "recursion no;" in the options block). In BIND 8, you should
also specify "fetch-glue no;"; otherwise the server may attempt to retrieve
glue information from the Internet during the test, slowing it down by an
unpredictable factor.
.SS "Constructing a query input file"
A \fBdnsperf\fR input file should contain a large and realistic set of
queries, on the order of ten thousand to a million. The input file contains
one line per query, consisting of a domain name and an RR type name
separated by a space. The class of the query is implicitly IN.

When measuring the performance serving non-terminal zones such as the root
zone or TLDs, note that such servers spend most of their time providing
referral responses, not authoritative answers. Therefore, a realistic input
file might consist mostly of queries for type A for names *below*, not at,
the delegations present in the zone. For example, when testing the
performance of a server configured to be authoritative for the top-level
domain "fi.", which contains delegations for domains like "helsinki.fi" and
"turku.fi", the input file could contain lines like
.RS
.hy 0

.nf
www.turku.fi A
www.helsinki.fi A
.fi
.hy
.RE

where the "www" prefix ensures that the server will respond with a referral.
Ideally, a realistic proportion of queries for nonexistent domains should be
mixed in with those for existing ones, and the lines of the input file
should be in a random order.
.SS "Constructing a dynamic update input file"
To test dynamic update performance, \fBdnsperf\fR is run with the \fB\-u\fR
option, and the input file is constructed of blocks of lines describing
dynamic update messages. The first line in a block contains the zone name:
.RS
.hy 0

.nf
example.com
.fi
.hy
.RE

Subsequent lines contain prerequisites, if there are any. Prerequisites can
specify that a name may or may not exist, an rrset may or may not exist, or
an rrset exists and its rdata matches all specified rdata for that name and
type. The keywords "require" and "prohibit" are followed by the appropriate
information. All relative names are considered to be relative to the zone
name. The following lines show the 5 types of prerequisites.
.RS
.hy 0

.nf
require a
require a A
require a A 1.2.3.4
prohibit x
prohibit x A
.fi
.hy
.RE

Subsequent lines contain records to be added, records to be deleted, rrsets
to be deleted, or names to be deleted. The keywords "add" or "delete" are
followed by the appropriate information. All relative names are considered
to be relative to the zone name. The following lines show the 4 types of
updates.
.RS
.hy 0

.nf
add x 3600 A 10.1.2.3
delete y A 10.1.2.3
delete z A
delete w
.fi
.hy
.RE

Each update message is terminated by a line containing the command:
.RS
.hy 0

.nf
send
.fi
.hy
.RE
.SS "Running the tests"
When running \fBdnsperf\fR, a data file (the \fB\-d\fR option) and server
(the \fB\-s\fR option) will normally be specified. The output of dnsperf is
mostly self-explanatory. Pay attention to the number of dropped packets
reported - when running the test over a local Ethernet connection, it should
be zero. If one or more packets has been dropped, there may be a problem
with the network connection. In that case, the results should be considered
suspect and the test repeated.
.SH OPTIONS

\fB-a \fIlocal_addr\fB\fR
.br
.RS
Specifies the local address from which to send requests. The default is the
wildcard address.
.RE

\fB-b \fIbufsize\fB\fR
.br
.RS
Sets the size of the socket's send and receive buffers, in kilobytes. If not
specified, the operating system's default is used.
.RE

\fB-c \fIclients\fB\fR
.br
.RS
Act as multiple clients. Requests are sent from multiple sockets. The
default is to act as 1 client.
.RE

\fB-d \fIdatafile\fB\fR
.br
.RS
Specifies the input data file. If not specified, \fBdnsperf\fR will read
from standard input.
.RE

\fB-D\fR
.br
.RS
Sets the DO (DNSSEC OK) bit [RFC3225] in all packets sent. This also enables
EDNS0, which is required for DNSSEC.
.RE

\fB-e\fR
.br
.RS
Enables EDNS0 [RFC2671], by adding an OPT record to all packets sent.
.RE

\fB-f \fIfamily\fB\fR
.br
.RS
Specifies the address family used for sending DNS packets. The possible
values are "inet", "inet6", or "any". If "any" (the default value) is
specified, \fBdnsperf\fR will use whichever address family is appropriate
for the server it is sending packets to.
.RE

\fB-h\fR
.br
.RS
Print a usage statement and exit.
.RE

\fB-l \fIlimit\fB\fR
.br
.RS
Specifies a time limit for the run, in seconds. This may cause the input to
be read multiple times, or only some of the input to be read. The default
behavior is to read the input once, and have no specific time limit.
.RE

\fB-n \fIruns_through_file\fB\fR
.br
.RS
Run through the input file at most this many times. If no time limit is set,
the file will be read exactly this number of times; if a time limit is set,
the file may be read fewer times.
.RE

\fB-p \fIport\fB\fR
.br
.RS
Sets the port on which the DNS packets are sent. If not specified, the
standard DNS port (53) is used.
.RE

\fB-q \fInum_queries\fB\fR
.br
.RS
Sets the maximum number of outstanding requests. When this value is reached,
\fBdnsperf\fR will not send any more requests until either responses are
received or requests time out. The default value is 100.
.RE

\fB-Q \fImax_qps\fB\fR
.br
.RS
Limits the number of requests per second. There is no default limit.
.RE

\fB-s \fIserver_addr\fB\fR
.br
.RS
Specifies the name or address of the server to which requests will be sent.
The default is the loopback address, 127.0.0.1.
.RE

\fB-S \fIstats_interval\fB\fR
.br
.RS
If this parameter is specified, a count of the number of queries per second
during the interval will be printed out every stats_interval seconds.
.RE

\fB-t \fItimeout\fB\fR
.br
.RS
Specifies the request timeout value, in seconds. \fBdnsperf\fR will no
longer wait for a response to a particular request after this many seconds
have elapsed. The default is 5 seconds.
.RE

\fB-T \fIthreads\fB\fR
.br
.RS
Run multiple client threads. By default, \fBdnsperf\fR uses one thread for
sending requests and one thread for receiving responses. If this option is
specified, \fBdnsperf\fR will instead use N pairs of send/receive threads.
.RE

\fB-u\fR
.br
.RS
Instructs \fBdnsperf\fR to send DNS dynamic update messages, rather than
queries. The format of the input file is different in this case; see the
"Constructing a dynamic update input file" section for more details.
.RE

\fB-v\fR
.br
.RS
Enables verbose mode. The DNS RCODE of each response will be reported to
standard output when the response is received, as will the latency. If a
query times out, it will be reported with the special string "T" instead of
a normal DNS RCODE. If a query is interrupted, it will be reported with the
special string "I".
.RE

\fB-x \fIlocal_port\fB\fR
.br
.RS
Specifies the local port from which to send requests. The default is the
wildcard port (0).

If acting as multiple clients and the wildcard port is used, each client
will use a different random port. If a port is specified, the clients will
use a range of ports starting with the specified one.
.RE

\fB-y \fI[alg:]name:secret\fB\fR
.br
.RS
Add a TSIG record [RFC2845] to all packets sent, using the specified TSIG
key algorithm, name and secret, where the algorithm defaults to hmac-md5 and
the secret is expressed as a base-64 encoded string.
.RE
.SH AUTHOR
Nominum, Inc.
.SH "SEE ALSO"
\fBresperf\fR(1)
